Allison Woods is an extensive Piedmont hardwood forest covering one thousand acres along the South Yadkin River in northern Iredell County. The tract was originally settled by the Allison family in the mid 1740's. The property was engineered by Major William Locke Allison, 5th generation owner. In the 1930's, Major Allison oversaw the construction on many fabulous stone buildings, gardens, lakes and ponds. In 1995, a small section of the developed property was designated as a National Historic Site.

The woodland character is typical of a large property historically devoted to agriculture and forestry. Despite the historical disturbances, there are many natural landscapes still intact. Allison Woods rolling topography descends from 915 feet above sea level at its highest point (marked by the windmill) to 730 feet along the South Yadkin River.

Mesic mixed hardwood forest occupies a great deal of the landscape: steep-sided hollows created by tributaries to the South Yadkin River and North-facing bluffs create the cool moist conditions favored by Red Oak (Quercus Rubra), Beech (Fagus Grand folia), and Tulip Poplar (Linodendron Tulipifera). The low sloped and hollows and opening up to the floodplain of the South Yadkin River are very diverse. The herbaceous plants reach the highest species diversity over the Wilkes series soils. Dikes of mafic rock are present throughout the low woods and are indicated by wildflowers such as May apple (Podophyllum Peltatum). The umbrella shaped leaves of May apple interlock and form carepts from the foot slopes onto the river terrace. Beneath the leaves a single white flower is hidden from view. Wild Geraniums (Geranium Maculatum) form patches of 5 petaled pink blossums. Also present are Blue Star (Amsonia Tabemaemonta), Bugbane (Cimicifuga Racemosa), Solomon's Seal (Polygonum Biflorum), Canada Richweed (Collinsonia Canadensis), Large Flower Skullcap (Scuterraria Serrata) and Toothwart (Dentaria Diphylla - Cardamine).

Higher on the slopes, the change in canopy dominants indicates slightly drier soil conditions with increasing apprearce of White Oak (Quercus Alba) and Scarlet Oak (Quercus Coccinea). This dry-mesic oak hickory forest was historically the most extensive covering all the now cut over upland ridges. Most of the cutting was in response to damages and tree loss of Hurricane Hugo. Many of the sites are recovering nicely due to salvage efforts of the Allison family. The driest southwest-facing slopes are dominated by large Short Leaf Pine (Pinus Echinata), some reaching almost two feet in diameter. In these dry areas are found Downy False Foxglove (Aureolaria Virginica), Coreopsis (Coreopsis Auriculata), Bracken Ferns (Pteridicum Aquilinim) and clusters of Lady Slippers (Cypripedium Acaule). St. Andrew's Cross (Hypericum Hypericoides) is a deciduous shrub with yellow tassel-like flowers dots the forest edge. The most common herb is False Solomon's Seal (Smiliacina Racemosa). In the summer, the forest floor becomes punctuated with the white inflorescences of Devil's Bit (Chamaelirium Luteum) which resemble tiny lily-like flowers arranged in tall thin spikes.

Following the old spring house down to the South Yadkin River are patches of Piedmont/Low Mountain Alluial Forest Spicebush (Lindera Benzoin). The forest canopy on the South Yadkin River floodplain is dominated by Sycamore (Platanus Occidentalis), River Birch (Betula Nigra) and Sweet Gum (Liquidambar Styraciflua). A dense sub canopy of Box Elder Maple (Acer Negundo) is present. On the banks of the river are also found the leafy stems of the River Oats (Uniola Latifolia).

The floodplain section of the lowlands lies over the Wehadkee series soils (typically shallow to ground water). Here is where there is a large stand of Cottonwood (Poplus Deltoides). The canopies of the Cottonwoods intercept almost all of the sunlight and only patches of Jump Seed (Tovara Virginia) and the rare openings to the light are Orange Jewelweed (Impatiens Capensis). With the floodplain in the little higher level it is dominated by Willow Oak (Quercus Phellos) and large Red Oak (Quercus Shumardii). The thick to clay subsoil of the Wehadkee series soils is responsible for the Fen, the streams flow is on the soil surface. The major shrubs are Alder (Alnus Serrulata), Swamp Rose (Rosa Palustris), Swamp Dogwood (Comus Amomum), Buttonbush (Chephalanthus Occidentalis) and Black Willow (Salix Nigra), Green Arrow-Arum (Peltandra Virdinica) and Duck Potato (Sagittatum Latifolia) are the dominate herbs on the open waterways. Tear Thumb (Polygonuim Arifolium), Knotweed (Polygonum Hydropiperoides), Arrow-Leaf Tear Thumb (Polygonuim Arifollium) are also present. The shallow Fen contains Water Plantain (Alisma Subcordatum), Addlers Tongue Ferns (Ophioglossum Vulgatum), St. John's Wort (Hypericum Walteri) and Swamp Skullcap (Scutellaria Later Flora) and Joe-Pye Weed. Near the mouth of the valley and the end of the Fen, the vegetation changes quickly, with more bottom land species appearing such as Spice Bush, False Nettle (Boehmeria Cylindrica) and Coneflowers (Rudbeckia Lacinata). The valley floor is densely carpeted with Marsh Dew flowers (Aneilema Keisak).